Remote control system for a trimming locomotive



Sept. 6, 1960 .1. G. KARLET 2,951,452

REMOTE CONTROL SYSTEM FOR A TRIMMING LOCOMOTIVE Filed April 5, 1957 5Sheets-Sheet 1 FIG. I. GENERAL LAYOUT INVENTOR.

J. G. KARLET 1; BY

HIS ATTORNEY J. G. KARLET 2,951,452

REMOTE CONTROL SYSTEM FOR A TRIMMING LOCOMOTIVE Sept. 6, 1960 5Sheets-Sheet 2 Filed April 5, 1957 FIG. 2. CONTROL OFFICE TRANSMITTERSPT FOC 11* R. O T. m. R E 0 W E T I G! A A .|r L UL U P D W 0 A M R m HA u 8 22 O 46 O6 44 33 R R O O R EN EN E NRF N Dn A ||.F OEG OEG l. TNTN m E E O G G m R RE EF u P M v A A m N W T N A HIS ATTORNEY Sept. 6,1960 .I. G. KARLET 2,951,452

REMOTE CONTROL SYSTEM FOR A TRIMMING LOCOMOTIVE Filed April 5, 1957 5Sheets-Sheet 3 FIG. 3. LocoMoTIvE RECEIVER ANTENNA A2 U I EU, F:RECTIFIER RECTIFIER I I I47 l F 1 J I l l AUDIO AUD O LoCoMoTIvE AMPIFIER AMPLIFIER MOTOR CONTROL kl AR CARRIER RECEIVER AND AMPLIFIERBATTER'ES DEMODULATOR HSB CA BATTERY CHARGER I Cl T LI 1 sPT :l-ZIl-RA IMT 'TQQ 5W HSG R G INVENTOR.

J. G. KARLET BY gzww HIS ATTORNEY J. G. KARLET Sept. 6, 1960 REMOTECONTROL SYSTEM FOR A TRIMMING LOCOMOTIVE 5 Sheets-Sheet 4 Filed April 5,1957 INVENTOR. J. G. KARLET Tmssmom wmwfi El a: 22292 m6; wmw

HIS ATTORNEY J. G. KARLET Sept. 6, 1960 REMOTE CONTROL SYSTEM FOR ATRIMMING LOCOMOTIVE Filed April 5, 1957 5 Sheets-Sheet 5 INVENTOR. J. G.KARL-ET ATTQRNEY r r 2,951,452 1 Patented Sept. 6, 1960 REMOTE 'CUNTROLSYSTEM FOR A G LOCOMOTIVE Joseph G. Karlet, Roanoke, Va., assignor toGeneral Railway Signal Company, Rochester, NY.

Filed Apr. 5, 1%7, Ser. No. 650,934 7 "Claims. (or. 104-26) Thisinvention relates to a control system for a remotely controlledlocomotive and more particularly concerns a control system for aremotely controlled trimming locomotive in a railroad car classificationyard.

In railroad classification yards, freight cars received from incomingtrains are disconnected from the trains and reclassified as to furtherdestinations. The yard includes a large number of classification tracksconnected by switches to a main track. A control tower is centrallyprovided, wherein an operator controls the operation of the switches toroute the incoming cars to designated classification tracks. Theimparting of movement to the cars on the main track to carry them totheir respective classificat-ion tracks is normally effected byproviding a hump upon which the cars are pushed, and then disconnected,permitting them to run free down the inclined portion of the hump togather the speed necessary to carry them to their respectiveclassification tracks. However, because of certain factors which afiiectthe free movement of the cars, such as weight, frictionalcharacteristics of the individual cars, weather, wind, and the conditionof the tracks, cars will occasionally stop short of their intendeddestinations, thereby preventing the dispatching of subsequent cars overthe hump or onto a respective classification track. When a car isprematurely stopped between the hump and its respective classificationtrack, a trimming locomotive, under the control of an engineer, isemployed to push the car to its intended destination.

An object of this invention is to provide a control system for aremotely controlled trimming locomotive in a railway car classificationyard.

Another object of this invention is to provide a trmming locomtive in arailroad car classification yard controlled by carrier waves transmittedfrom the control tower.

Another object of this invention is to provide a spur track storagelocation for the trimming locomotive provided with means forautomatically charging the batteries of the trimming locomotive when itis at rest.

A further object of this invention is the provision of means forpreventing the control tower operator from operating the trimminglocomotive when there is an unsafe traflic condition existing in theclassification yard.

A still further object of this invention is the provision of meansinherent in the trimming locomotive for stopping the trimming locomotivewhen it occupies a predetermined position on a spur track storagelocation.

A still further object of this invention is to provide a remotelycontrolled trimming locomotive for a railroad classification yard whichlocomotive automatically brakes its forward and reverse movement uponthe deenergization of the driving motor.

Other objects, purposes and characteristic features of the presentinvention will be in part obvious from the accompanying drawings and inpart pointed out as the description progresses.

In describing the invention in detail, reference is made to theaccompanying drawings in which similar letter reference characters areused to designate similar parts of the organization, and in which:

Fig. 1 illustrates the general layout of a railroad car classificationyard provided with the present invention;

Fig. 2 illustrates the organization of apparatus at the control ofiicefor the remote control of the trimming locomotive;

Fig. 3 illustrates the organization of the apparatus located on thetrimming engine, and also shows the organization of the apparatuslocated adjacent the spur track which cooperates with the trimminglocomotive; and

Figs. 4A and 4B illustrates the motor control circuits which control theoperation of the trimming locomotive.

For the purpose of facilitating the disclosure of the present inventionas to its mode of operation, schematic wiring diagrams have been used toillustrate the circuit organization rather than attempting to show thespecific structure and arrangement of parts that will be employed inpractice. Rather than to show wiring connections to all sources ofenergy, the symbols and have been used to indicate connections to therespective positive and negative terminals of suitable batteries, orother sources of direct current.

With reference to Fig. l, the track layout for a railroad classificationyard is illustrated wherein the cars to be classified travel in thedirection of the arrow D on the main track MT. The cars are pushed tothe crest of the hump and are then free rolling down the inclined maintrack MT and selectively routed to a respective classification trackCLT. The control tower CTO contains control equipment which actuatescertain switches W in accordance with the intended destination of arespective freight car to a classificaton track CLT.

A trimming locomotive is normally located on a spur track SPT adjacenttothe track MT. Although in the present application, the spur track isshown below the crest of the hump, it is understood that it can belocated at any convenient point in the classification yard according tothe individual needs of practice. Spur switch SW, capable of beingoperated to a normal or reverse position, is provided, to connect thespur track SPT to the main track MT. With the switch SW in a reverseposition, a route is provided for the ingress or egress of thelocomotive from the track SPT. When the switch SW is in a normalposition, a route is provided for the cars to be classified.

A hump signal HSG capable of displaying stop and proceed aspects iscontrolled by an operator in the control tower CTO and is provided tocontrol the approach of cars onto the hump crest. When the signal HSGdisplays a stop aspect, cars to be classified are not allowed toapproach the hump crest.

Transmitting apparatus as shown in Fig. 2 is located in the tower CTOfor transmitting a distinctive carrier frequency modulated by toneswhich are transmitted by the antenna A1 and are selectively received bya receiver located on the locomotive T. The locomotive T moves in eithera forward direction from the track SPT toward the classification tracksCLT, or in a reverse direction toward the main track MT, and eventuallythe track SPT, at either a fast or a slow rate of speed, in accord ancewith the distinctive frequency of the tones transmitted.

In operation, when a freight car to be classified has inadvertently cometo a stop between the hump HU and a classification track CLT, or on adesignated classification track CLT, the operator in the control towerputs the signal HSG to stop, operates the switch SW to a reverseposition, and operates the transmitter to transmit a distinctive tonewhich causes the locomotive to move in a forward direction from thetrack SPT, thereby eventually 3 causing the locomotive to push thestepped car to its intended destination.

The control operator then causes the transmitter to transmitanotherdistinctive tone which results in the reverse movement of the locomotiveT to a predetermined position on the spur track SPT. As will bedescribed in detail, the locomotive automatically stops at apredetermined location on the track SPT when it reaches the areaoccupied by the ramp RA by the operation of a reverse shut olfapparatus. The batteries BT shown in Fig. 3 which provide the energy forthe locomotive driving motors M1 and M2 are charged to their fullpotential by suitable charging apparatus CA, which apparatus is sodisposed as to be self-operated while thelocomotive T is at rest on thetrack SPT. p I

With reference to Fig. 2, the control office apparatus 4 for thetransmission of locomotive controls is illustrated in' CTO, Once thelever LC is moved to a designated position, it remains in that positionuntil normally operated to a different position. However any suitablecontrol lever may be employed. A self-restoring push button FP-B isprovided to control the speed of the locomotive T. The manual depressionof button FPB results in the increased speed of the locomotive T.

When the lever LC is in an extreme right-hand position, the locomotive Tis operated in a reverse direction, and when it is in a normal positionthe locomotive T is oper- T is operated in a forward direction. With thelever LC intermediate between the left and right-hand positions, thelocomotive T is deenergized, and at rest. When the push button FPB isdepressed the locomotive T is operated at a fast rate of speed, as forexample, 5 miles per hour and when it is in a normal position thelocomotive T is operated at a lower rate of speed, as for example, 3.5miles per hour.

The system herein proposed for the purpose of effecting the remotecontrol of the locomotive T consists of transmitting a continuouscarrier wave which is modulated by two distinct audio frequencies eitherindividually or simultaneously.

'In accordance with the transmission of controls for the locomotive T bythe operation of the control lever LC, a field ofiice control relay FOCor R-OC is picked up, which renders the output of a respective tonegenerator GP or GR effective to apply its output'to a suitable voltageamplifier, which amplified output is applied to the modulator, and theoutput of the modulator is applied to the carrier wave oscillator; thenthe modulated carrier wave is further amplified and the output of thepower amplifier is supplied to the antenna A1 for radiation to anappropriate receiver on the locomotive T. As the control lever LC hasbeen actuated to either a forward or reverse position the depression ofthepush button FPB causes the inactive tone generator to apply itsamplified output to the modulator which serves to operate the locomotiveT at a higher speed in the designated direction in accordance with theposition of the lever LC as will hereafter be described in detail.

'A relay RGP is energized in response to a stop or red aspect of thesignal HSG and it is deenergized in response to a proceed or greenaspect of the signal HSG. A switch repeater relay RWP is energized whenthe switch SW is in a reverse position and deenergized when the switchSW is in a normal position. A signal switch control relay GWC isprovided to control the output of the modulator in accordance with thepick-up condition of the relay RWP and the relay RGP.

When the relays RGP and RWP are energized, a circuit is completedextending from and including the front contact 21 of relay RGP, thefront contact 22 of ,4 relay RWP, and the winding of the signal controlrelay GWC, to When the relay GWC is energized the front contact 23 ofrelay GWC is closed which completes a circuit allowing the plate voltagesupply 24 of the modulator to become efiective. Therefore, it isapparent that the tone generators GF and GR are ineffective intransmitting a tone when the signal HSG displays a proceed aspect, orthe switch SW is in a normal position.

The forward oflice control relay FOC is provided for causing the tonesgenerated by the tone generator GP to be applied to the carrier wavetransmitting apparatus. A.

reverse office control relay ROC is provided for causing the tonegenerated by the tone generator GR to be applied to the carrier wavetransmitting apparatus.

In response to the operation of the lever LC to its lefthand or forwardposition, the forward office control relay FOC is energized by a circuitwhich extends from and includes contact 26 of lever LC in its forwardposition and the winding of relay FOC, to The relay FOC picks up andrenders the output of the tone generator GF efiective to modulate thetransmitted carrier wave by closing a circuit which extends fromterminal 44 of the tone generator GF, the front contact 27 or relay FOC,terminal 33 of the voltage amplifier, terminal 34 of the voltageamplifier, back contact 45 of relay ROC, and front con tact 28 of relayFCC to the terminal 46 of the tone generator GF. 1 7

When the control lever LC is operated to its right-hand or reverseposition, a reverse office control relay ROC is energized by a circuitwhich extends from and includes contact 26 of the lever LC inthe reverseposition and the winding of relay ROC, to When the relay ROC isenergized the tone generator GR is effective to modulate the carrierwave by closing a circuit which extends -from terminal 3% of the tonegenerator GR, the front'contact 31 of relay ROC, back contact 32 ofrelay FOC, terminal 33 ofthe voltage amplifier, terminal 34 of thevoltage amplifier, front contact 35 of relay ROC to terminal 36 of thetone generator GR.

After a control has been transmitted to cause the locomotive to moveforward in accordance with the particular audio frequency generated bythe tone generator GP, the operator can depress the button FPB whichpicks up the relay ROC by a circuit which extends from and includescontact 26 of lever LC in the reverse position, back contact 43 of thebutton lFPB and the winding of relay ROC, to to modulate the carrierwave with the frequency of the tone generator GR.

With the button FUB depressed, the tone generator GR and the tonegenerator GF are feeding their respective tones simultaneously andserially into the voltage amplifier by a circuit which extends fromterminal 44 of tone generator GF, front contact 27 of relay FOC,terminal 33 of the voltage amplifier, terminal 34 of the voltageamplifier, front contact 35 of relay ROC, terminal 36 of tone generatorGR, terminal 30 of tone generator GR, front contact 31 of relay ROC,from contact 32 of relay FOC, front contact 45 of relay R00, and frontcontact 28 of relay FCC to the terminal 46 of the tone generator GF.

' It is thus provided that in response to the picking up of the relaysFOC and/or ROC by the positioning of the lever LC and/or the actuationof the button FPB, one or both of the tone generators are renderedeffective to apply their output individually or simultaneously to amodulator for distinctively modulating the carrier wave. The duration ofthe modulation is governed by the length of time that the control leveris in either a right-hand or a left-hand position. The output of thepower amplifying portion of the carrier wave transmitter is supplied tothe antenna A1 for radiation to the. receiver of the trimming locomotiveT as is illustrated in Fig. 3.

In the event that-the remotely controlled locomotive is to be installedin a large classification yard, or where the needs of practice mayrequire the operation of a trimming locomotive to a distant location,suitable transmitting antennas may be installed in appropriate placesthroughout the yard and connected to the transmitter by various meanswhich are well known in the art.

The portion of apparatus located on the trimming locomotive to becontrolled as shown in Fig. 3.

With reference to Fig. 3 a receiving antenna A2 which receives theoutput of the antenna A1 is connected to a suitable receiving apparatuson the locomotive T.

As herein shown the modulated carrier wave is received through theantenna A2, amplified by the carrier amplifier, demodulated by aconventional demodulator, amplified by a tuned audio amplifier AF isdistinctively tuned to receive and amplify the demodulated audiofrequency currents generated by the tone generator GF of the transmitterto effect the energization of the forward receiver control relay F; andthe amplifier AR is distinctively tuned to receive and amplify thedemodulated audio frequency currents generated by the tone generator GRto effect the energization of the reverse receiver control relay R. Whenthe control ofiice transmitter Fig. 2) is simultaneously transmittingtones from GF and GR, both the relays R and F are energized. Relay F inthe motor control circuit as shown in Figs. 4A and 4B governs theoperation of the trimming locomotive in a forward direction, and therelay R controls the locomotive in a reverse direction.

There is provided a home stop switch HSB for removing circuit energyfrom the locomotive motor control circuit when the relay R is energizedand the locomotive is traveling in a reverse direction. The home stopswitch HSB is so disposed on the trimming locomotive that when thelocomotive reaches an area on the spur track, which area is controlledby a stationary ramp RA, the switch HSB cooperates with the raisedportion of the ramp RA to open the contact 48 of the switch HSB whichrenders the energized relay R ineffective to control the reversemovement of the locomotive, thereby causing it to stop. The frontcontact 47 of relay R is serially connected with the back contact 48 ofthe switch HSB so that the relay R in a picked up condition, isineffective in closing a circuit in the motor control apparatus throughthe front contact 47 when the switch HSB is in cooperative relationshipwith the ramp RA.

In operation, when the locomotive T is being operated in a reversedirection towards its spur track location the home stop switch HSB willengage the ram RA and bring the locomotive T to a stop at the properposition on the spur track SPT without further attention on the part ofthe operator which operation will be described in detail. It should alsobe noted that the home stop mechanism affects only the reverse controlof the locomotive.

Trolleys L1 and L2 are attached to the locomotive T and suitablyconnected to the batteries BT. Contacts C1 and C2 are located adjacentthe track SPT and so disposed as to frictionally engage the trolleys L1and L2.

When the locomotive T is in proper position the trolleys L1 and L2engage the contact mechanism C1 and C2, respectively, to recharge thebatteries when the locomotive T is at rest on the spur track SPT.Conventional means are provided for cutting out the battery charger whenthe battery is charged to its full potential.

Figs. 4A and 4B illustrate the control circuit for the driving motors M1and M2 which propel the trimming locomotive. The motors M1 and M2 are,for example, 50 HP. shunt wound motors which are directly geared to theaxles of the locomotive. The motor M1 is geared to the front axle andthe motor M2 is geared to the rear axle. Although shunt wound motors areused to drive the locomotive because they tend to run at a constantspeed, which gives the operator greater control over the trimminglocomotive other types of motors may be used according to the individualneeds of practice.

As illustrated in Fig. 4B, the motors M1 and M2 comprise armatures ATIand AT2, respectively and field windings FDI and FD2, respectively.

Storage batteries BT provide energy for themotors M1 and M2. The batteryis assumed to be an 88 cell storage battery capable of providing apotential of at least .117 volts under a no-load condition. In oneapplication of this invention battery cells which are commonly known asEdison cells having positive electrodes of nickel oxide flakes, andnegative electrodes of powdered iron, and an electrolyte consisting of adilute solution of potassium hydroxide are utilized. This type of cellis considered advantageous for the reason that it has a highkilowatt-hour capacity and can stand indefinitely in either a charged ordischarged condition without adverse effect on the batteries. However,other types of storage batteries may be used according to the needs ofpractice.

A local manual control lever TPL and a speed button SPB are provided onthe locomotive to locally operate the motor control circuit. The leverTPL is capable of being manually operated to a reverse, automatic, orstop position, and the button SPB when depressed is capable of causingthe locomotive T to operate at a faster rate of speed.

As previously described, the relay R (also shown in Fig. 3) is picked upin response to the output of the amplifier AR, which output iscontrolled by the manual operation of the control lever LC (see Fig. 2)to its reverse position; and the relay F is picked up in response to theoutput of the amplifier AF which output is controlled by the lever LC inits forward position.

A reverse repeater relay RP, a reverse selection relay RX, and a reversemotor control relay RM are provided to control the motors M1 and M2 inthe reverse direction of rotation. A forward repeater relay FP, aforward selection relay FX, and a forward motor control relay FM areprovided to control the motors M1 and M2 in their forward direction ofrotation.

A field control relay FL is provided to control the energization of thefields FDI and FD2 of the motors M1 and M2. A speed selection relay SP,a slow speed control relay SL and a fast speed control relay FT governthe selective speed of themotors M1 and M2. The reverse time delay relayRTD, the forward time delay relay FTD, and the dynamic braking relay DBare provided to control the braking of the motors M1 and M2 when therelays R and F are deenergized. A bell BL is provided to'continuallyring while the locomotive is operated in either a forward or reversedirection.

Assuming that the operator wishes to move the locomotive in a forwarddirection at a slow rate of speed the relay F is energized in responseto the previously mentioned operations of the transmitter and receiverin accordance with the position of the control lever LC. When the relayF is picked up it energizes the forward repeater relay FP by a circuitwhich extends from and includes front contact 49 of relay F, backcontact 50 of relay R, and the winding of relay FP, to When relay FF isenergized relay FX is energized by a circuit which extends from andincludes the front contact 51 of relay FP, back contact 52 of thereverse time delay relay RTD and the winding of the forward selectionrelay FX, to Upon the picking up of relay FX the forward time delayrelay FTD is energized by a circuit which extends from and includesfront contact 53 of relay FX and the winding of relay FTD, to When relayFTD is picked up the relay FL is energized by a circuit which extendsfrom and includes front contact 54 of relay FTD and the winding of thefield energizing relay FL, to When the relay FTP is picked up the relaySL is energized by a circuit Which'extends from the and includes thefront contact 54 ofrelay FTD, back contact 55 of relay SP, back contact56 of relay FT, and winding of relay SL, to The picking up of relay FLenergizes the field FBI and FD2 of the motors M1 and M2 by a circuitwhich extends from and includes the field windings FD1, F132, and frontcontact 57 of relay .FL to a commonlow voltage terminal 98 of thebatteryBT. When :relay. FL is picked up the forward motor control relay isenergized by a circuit which-extends from and includes front contact 59of relay FX, front contact 60 'of relay FL, back contact 61 of relay DB,and winding ofrelay FM, to The picking up of relay FM .energizes thearmatures AT1 and AT2 of the motors .M1 and M2hy a circuit which extendsfrom common terminal 98 of the battery BT, a front contact 62 of relayPM, the armatures AT2 and AT1, front contact'63 of relay. FM, frontcontact 64 of relaySL and the common -tern1inali66 of the battery BT.

At this point the motors M1 and M2 are driving the locomotive in aforward direction. If the operator wishes to increase the speed of thelocomotive, the button FPB is depressed which results in the picking upof the normally deenergized reverse receiver control relay R:asdescribed previously. When relay R is picked up a circuit for the relaySP is energized by a circuit which extends from and includes frontcontact 49 of relay F, front contact 86 of relay R and the winding ofrelay SP, to The picking up of the relay SP opens its back contact 55which deenergizes the previously pickedup relay SL and energizes therelay FT by a circuit which extends from and includes front contact 87of relay SP, back contact 88 of relay SL, and the winding of relay FT,to The picking up of the relay F1 and the dropping away of relay SLincreases the armature voltage of the motors M1 and M2 by closing ,acircuit which extends from common battery terminal 98, front contact 62of relay FM, armatures AT2 and AT1, front contact 63 of relay FM andfront contact 85 of relay FT to the negative terminal 92 of the batteryBT. When relay R was picked up subsequent to the picking up of the relayF a reverse control on the motor was prevented by the open condition ofthe back contact 67 of relay F. Also, relay FP remains in its picked upposition by an alternate circuit which extends from' and includes frontcontact 49 of relay F, front contact 93 of relay PP and the winding ofrelay FP, to Thus it can be seen that the circuit is so arranged thatthe picking up of one of the demodulating relays with one already in apicked-up condition energizes only the speed control relay SP. and

the fast relay PT. If the locomotive had been traveling in a reversedirection and the speed were .to be increased the relay F would have,subsequently picked up and the relay RP would have remained energized byan alternate circuit which extends from and includes the back contact 48of the switch HSB, the front contact 47 of the relay R, the frontcontact 94 of the relay RP, and the winding of the relay RP to Assumingthat the operator wishes to bring the locomotive to a stop, the controllever LC is moved to its intermediate position as hereinbefore mentionedthereby resulting in the deenergization of both the relays F and R. Thedropping away of the relays F and R results in the picking up of thedynamic braking relay DB by a circuit which extends from and includesthe front contact 54 of the forward time delay relay FTD, the backcontact 95 of the relay FX which has become deenergized upon thedropping away of the relay FP, the back contact 96 of relay RX and thewinding of relay DB to It should be noted that the relay FTD is a slowdrop-away relay and remains picked up for a length of time after theforward receiver control relay F is deenergized. In one application ofthis invention the FTD relay is designed to remain picked up for aperiod of 10 seconds after the opening of its pick-up circuit although ashorter or longer drop-away time could be used as the needs of practicemay dictate. It should also be noted that the field energizingvrelay FLremains picked up during the timethat the relay F';I'D

is energized. The picked-up condition of the dynamic braking relay DBcloses its front contact 97 which dynamically brakes the motors M1 andM2 for a period of 10 seconds. This conventional method of braking iseffective in that the induced voltage of the armatures AT1 and AT2 willcause a current to flow through the dynamic braking resistance therebyproducing a distinct retarding torque.

In causing the locomotive to return to its spur track location SPT theoperator actuates the lever LC in the control oliice to its reverseposition, and the reverse control relay R is picked up as previouslydescribed.

When the relay R is picked up, the relay RP is energized by a circuitwhich extends from and inlcludes the back contact 48 of the home stopswitch HSB, the front contact47 of the relay R, the back contact 67of-the relay'F and the Winding of relay RP to The picking up of therelay RP energizes the relay RX by a circuit which extends from andincludes the front contact 68 of relay RP, the back contact 69 of therelay FTD, and the winding of the relay RX to When the relay RX picks upthe relay RTD is energized by a circuit which extends from and includesfront contact 70 of relay .RX and the Winding of relay RTD to When-therelay RTD is picked up it energizes the relay FL by a circuit whichextends from and includes front contact 71 of relay RTD and the Windingof relay FL to The picking up of the relay FL energizes the fieldwindings FD1 and FD2 of the motors M1 and M2 as previously described.The picking up of relay FL completes a circuit for energizing the relayRM which extends from. and includes the front contact 72 of the relayRX, the front contact 73 of the relay FL, the back contact 74 of therelay DB, and the winding of the relay RM to The picking up of the relayRM completes a circuit for energizing the armaturcs AT1 and AT2 of themotors M 1 and M2 which extends from the common terminal 98 of thebattery BT, a front contact 89 of the relay RM, the armatures AT1 andATZ, a front contact 90 of relay RM, the front contact 64-of relay SL,and the common terminal 66 of battery BT.

If the operator should wish to increase the speed of the locomotivetraveling in a reverse direction the actuation of the push button FPB(of Fig. 2) results in the picking up of the receiver control relay Fwhich causes an increased voltage to be applied to the armatures of themotors M1 and M2 by a circuit previously described for the increase inspeed of the locomotive traveling in a forward direction.

When the locomotive returns to its spur track SPT over the switch SW ina reverse position the switch mechanism HSB cooperates with the ramp RAas previously described, opening the back contact 48 of the switch HSBthereby deenergizing the reverse repeater relay RP, and removing thesource of potential from the armatures AT1 and T2 of the motors M1 andM2. The reverse time delay relay RTD has operating characteristicssimilar to the relay FTD which dynamically brakes the motors M1 and M2for an approximate period of 10 seconds after the reverse control isremoved. The relay RTD energizes the relay DB by a circuit which extendsfrom and includes front contact 71 of the relay RTD, back contact of therelay FX, back contact 96 of the relay RX and the winding of relay DB toUnder proper conditions thebattery charging apparatus is effective tocharge the battery BT as previously described. It should be noted atthis time that the bell BL is ringing during the time the locomotive ismoving in either a forward or reverse direction. The bell is. energizedby a circuit which extends from and includes the front contact or 99 ofthe relay PM or RM respectively and the winding of the bell BL to v Thetest control. level TPL when manually operated to its forward. positionenergizes the relay FX by a circuit whichextends from. and includes thecontact 81 of 9, the'lever in' its forward position, back contact 52 ofrelay and the winding of relay FX to When the lever TPL -is operated toits reverse position, it energizes relay RX by a circuit which extendsfrom and includes contact 82 of lever TPL, back contact 69 of relayFI'D, and the winding of relay RX to The manual depression of the speedpushbutton SPB energizes the relay S P by a circuit which extends fromand includes the contact 83 of'button 'SPB, and the winding of relayhot-o. V

Although this embodiment of the present invention employs a space radiofor communication of the respective tones between control ofiice and thelocomotive, it is to be understood that other forms of communication ofthesetones may be employed, such as the tones being applieddirectlyor'indirectly to the track rails. It is to be also understood that otherforms of motive power may be utilized for propelling the locomotive, asfor example an internal combustion engine.

Having thus described a remote control system for a trimming locomotivein a classification yard, it is tobe understood that variousadaptations, alterations, and modifications may be applied to thespecific form shown to meet the requirements of practice without in anymanner departing from the spirit or scope of the present inventionexcept as limited by the appendingclaims.

WhatI claim is:

1. In a railway car classification system including a main trackconnected to a plurality of classification tracks, a signal operable todisplay a stop and a proceed aspect for regulating the approach oftraffic from said main track to said classification tracks, a relaymeans operated in response to the aspect displayed by said signal, aspur track connected to said main track, a trimming locomotive normallyat rest on said spur track, a prime mover located on the locomotive formoving the locomotive from the spur track to the main track when theprime mover is energized, a first circuit means for energizing the primemover, and a second circuit means controlled by said relay means whensaid signal displays a stop aspect for controlling the energization ofsaid first circuit means.

2. In a railway classification system including a main track connectedto a plurality of classification tracks, a control office, a signaloperable to display a stop and a proceed aspect adjacent said main trackfor governing the approach of trafiic on said main track, a spur track,a spur switch connecting said spur track to said main tracks, a trimminglocomotive normally at rest on said spur track, an electric motordrivably attached to said locomotive, a detection control relay locatedon said locomotive, a circuit means responsive to the operation of thedetection control relay for activating said electric motor, carrier wavetransmitting means located at the control ofiEice active to transmit amodulated carrier wave of a distinctive frequency, receiving apparatuson said locomotive responsive to a distinctive modulated frequency forenergizing said detection control relay, and circuit means responsive tothe aspect displayed by said hump signal for controlling thetransmission of said modulated carrier wave.

3. In a railroad classification yard including a main track connected toa plurality of classification tracks, a signal operable to display astop and proceed aspect for regulating traflic from said main track tosaid classification tracks, a relay means distinctively operated inresponse to the aspect displayed by said signal, a spur track connectedto said main track, a trimming locomotive normally at rest on said spurtrack, a motor driving means located on said trimming engine for movingsaid trimming engine onto said main track, a pulse transmitting meanslocated at a central point, a manually operable means located in saidcentral point, a first circuit means responsive to said manuallyoperable means for activating said transmitting means only when saidsignal relay means is operated in response to a stop aspect of saidsignal, a pulse receiving means on said locomotive for receivingtransmitted pulses, and circuit means responsive to said transmittedpulses for activating said motor driving means.

- 4. In a railway car classification system including a main trackconnected to a plurality of classification tracks, a control oflice, asignal for regulating the approach of trafiic from said main track tosaid classification tracks, signal circuit means for operating saidsignal to display a stop and a proceed aspect, a spur track connected toone of the said tracks, a locomotive capable of being remotely operatedfrom said control office and able to move in a forward direction fromthe spur track over said main track to a respective classification trackand in a reverse direction from a respective classification trackoversaid main track onto the spur track, a stationary contact meansadjacent said spur track, a circuit breaking means located on saidlocomotive effective to deenergize the locomotice in response to thestationary contact means when the locomotive is traveling in a reversedirection on said spur track, and a circuit means responsive to thesignal circuit means for permitting the locomotive to be operated in aforward direction only when the signal displays a stop aspect.

5. In a railroad classification yard system including a main trackconnected to a plurality of classification tracks by track switches, acontrol office, a spur track, a spur switch connecting the spur track tosaid main track, a signal capable of being operated to display a stopand proceed aspect for regulating trailic from the main track to arespective classification track, a trimming locomotive, a motor locatedon the trimming locomotive capable of driving the locomotive in aforward direction from the spur track onto said main track and in areverse direction from the main track onto the spur track, a manuallyoperable means, a carrier wave transmitting means capable of selectivelytransmitting carrier currents of distinctive frequency, a carrier wavereceiving means located on the locomotive capable of receivingdistinctive transmitted carrier waves, a first circuit means for causingthe transmitter to transmit a certain frequency in accordance with theoperation of the manually operable means, a second circuit means foroperating the locomotive in a forward and reverse direction in responseto the reception of a certain transmitted frequency, a circuit breakingmeans located 011 the locomotive for deenergizing the motor when thelocomotive is moving in a reverse direction, a fixed contact elementdisposed adjacent the spur track to actuate the circuit breaking meanswhen the locomotive is on the spur track, and a third circuit means forrendering the transmitting means inefiective to operate rthe locomotivewhen the trafiic controlling signal displays a stop aspect.

6. In a railroad classification system including a track layout having amain track leading to a plurality of classification tracks and alsohaving a spur track connected to said main track directly leading tosaid plurality of classification tracks, a trimming locomotive of theself-propelled controllable type operable over said tracks but normallylocated on said spur track, radio receiving 'means on said locomotiveoperable upon the reception of different distinctive signals to controlthe operation of said trimming locomotive in forward and reversedirections and to stop, radio transmitting means at a remote locationand manually controllable to transmit any one of said difierentdistinctive signals for reception by said radio receiving means on saidlocomotive, a normally closed electric switch on said locomotive openedin accordance with the occupancy by said locomotive of a particularportion of said spur track, said radio receiving means being renderedefiective to operate the locomotive selectively in a forward or reversedirection when said electric switch is closed but only forward when theswitch is open, and wayside means in said particular portion of saidspur track for opening said electric switch on said locomotive.

7. In a railroad classification system including a track layout having amain track leading to a plurality of classification tracks and alsohaving a trimmer locomotive track connected through a track switchtosaid main track directly leading to said plurality ofclassificationtracks,

a trimmer locomotive of the self propelled remote control:

means and acting in response thereto for controlling the,

operation of said locomotive, and switch position indicating and controlmeans at the remote point actuated in accordance with the position ofsaid track switchfor rendering said radio transmitting means effectiveonly when said track switch is indicated as being in a predeterminedposition to permit the trimming locomotive to enter the main track.

References Cited in the filev of this patent UNITED STATES-PATENTS814,498 Woodford Mar. 6, 1906 12 Bigby July 1-9, 1940 Sollman May 30,1911; I Spierewfki Nov. 25,, 1913 Hudson 2 ;Feb. 15, 1916 Stuart June12, -19 17, Boemper Aug. 21, 1917 Betz May-14, 19:18; Mancha Ian.11,1919; Loveridge Nov. 30, T1926 FailOI' Aug. 28, 192;;- AlexandersonFeb. :1 1-,; 1 930 Aspinvvall Dec. 30, 1930 Hart Feb. 23, 19,3 2; NeumanJan. 22, 15135: Hirshfield' Dec. M, 193 5,v Cardoza 2 ,Mar. 9,,1937Dinga Apr. 2, 1945- Milne 2 Sept. 5,;19 $0 Purington Sept; 19, l;9 50Harnischfeger et a1. ,Nov. 14, Mayle Aug. '12,; U Storsand 2 Jan 2 7, fH Heil {14, Myles l8, Storsand Iain-22, Rees et al. a,l \ilay 57Eldridge Nov. 4,; r959

